#include <REGX52.H>
void Delay(unsigned int xms)		//@12.000MHz
{
	
	
	unsigned char i, j;
  while(xms)
	{	
		i = 2;
		j = 239;
		do
		{
			while (--j);
		} while (--i);
	  xms--;
	}
}


void main()
{
	while(1)
	{
		if(P3_1==0)
		{
			Delay(20);
			while(P3_1==0);
			Delay(20);
			P2_0=~P2_0;
		}
		
	}	
}
